Search for and extract specific data from emails and copy to text file

hi I need something written that will monitor an email inbox and if emails come in from a specific email address it will search that email immediately and extract specific data (3 items) and copy it to a text file in a defined format. Speed is critical so software must execute as soon as the email arrives. Finally it was call another program that has already been written (which then uses the contents of the text file. When one email has been dealt with it will reset and wait for the next email and repeat the process copying over the previous text file with the data extracted from the new email. All emails will be similarly structured so should be easy to define rules for identifying the data to be extracted. The software needs to run on a VPS running windows server 2008. thanks